1. Field of the Invention
The present invention relates to a method for etching and strengthening a side edge of an OGS (One-Glass-Solution) touch panel, and in particular to a method for carrying out edge etching and strengthening of an OGS touch panel with one-time film lamination.
2. The Related Arts
Touch screens have very wide applications, such as tablet computers, mobile phones, notebook computers, tourist guide systems, and vending machines. Such an interface is convenient and requires no additional input device and is straightforward for general users so that the market thereof is still expanding and various novel styles have been proposed. According to the operation principles that are employed to detect the touch points, the touch screens are classified as resistive screens, capacitive screens, optic type screens, and wave type screens, among which the capacitive screens are most widely used in the current market.
A conventional touch screen is composed of two electrically conductive layers between which spacers and electrodes are arranged. The top layer is often a plastic sheet of polyesters that has inner surface on which an electrically conductive metal layer is formed, while the bottom layer is a glass substrate carrying an electrically conductive material. Formed between and spacing the glass substrate and the polyester sheet is another layer that is a tiny spacer layer made up of smaller plastic spacers made of polyester and forms a plurality separation lines. The separation lines extend on the glass substrate to define an X-axis, while a Y-axis is formed on the polyester sheet. When a point of a finger or a stylus applies a force to the touch screen, an electronic controller arranged beside the electrically conductive layers detects the X-axis and Y-axis coordinates of the touch point and a response is made on the screen.
The mainstream of the current touch screen market is OGS (One/Single Glass Solution), which is also referred to as Touch on Lens. The OGS touch panels have advantages of cost and manufacture and satisfy the demands of electronic technology products for being light-weighted, thin, and compact for the outside appearance thereof. The international manufacturers of mobile phones and tablet computers all start to use it one after one.
The OGS touch panel is generally structured by combining a touch glass sheet with a protective glass sheet to form a single glass sheet, wherein touch sensors are directly formed on the protective glass sheet, so that the touch function that is provided by the touch glass sheet and the strength that is provided by the protective glass sheet are integrated on the same single glass sheet.
The OGS touch panel comprises multiple electrically conductive layers coated on an inner surface of the protective glass sheet to reduce the amount of glass used, simplify a lamination process of touch control modules, and thus improve the yield rate of manufacture. In addition to the reduction of cost, most importantly, the glass sheets used can be made relatively light-weighted, thin, and small, having a substantial reduction of thickness and weight as compared to the two-glass-sheet structures, so as to better suit the needs of the touch screen market and also enhance light transmittance, and posing no issue of necessary modification of the existing manufacturing processes for LCD panels, and allowing for production in a small-volume large-variety manner. The OGS touch panels are superior, in respect of material and software and hardware manufacturing techniques, to the conventional two-glass-sheet-laminated substrates (G/G type) and glass-film laminated substrates (G/F type).
However, the OGS touch panels still suffer certain issues of manufacturing processes thereof, which should be properly handled. For example, a major difficult of the OGS manufacturing process is how to eliminate edge defects of glass sheets. A conventional manufacturing process is such that an OGS touch panel, after being subjected to cutting, is laminated with a protective film and is then subjected to a strengthening operation. However, in such a conventional way of manufacturing, it needs to perform several times of film replacement. This requires substantial facility and manpower for film replacement and the cost is high. Further, problems, such as scratches, contamination, surface damages of glass sheets, and damages of circuits, may occur during the replacement of the films.
Cutting the reinforced glass sheets in the manufacturing processes in generally difficult for the reinforced glass sheets have hardness higher than the regular glass sheets. This may cause high wear of the cutting tools. Thus, the expense of cutting is high and the yield rate is low. Further, it often occurs that the cutting processes cause cracking and breaking in edges of the reinforced glass sheets, leading to capillary and tiny fractures. Such fractures greatly lower the strength of the glass sheet. A solution that is commonly adopted in some manufacturing processes is to first cut and then reinforce, and afterwards, film lamination and etching are carried out. Such a solution still suffers a low efficiency and a high expense for mass production.